This disclosure relates to transparent metal oxide compositions, methods of manufacture thereof and to articles comprising the same.
Transparent semiconductors are used in thin film transistors (TFT) as backplanes in electronic display applications. The greater the transparency of the semiconductor, the greater the amount of light which is able to pass through the semiconductor.
Transparent oxides have electronic and optical properties that allow them to be transparent to visible light (i.e., optically transparent) when used in thin films. These transparent oxides may also have electrically conducting or semi-conducting properties. A transparent oxide semiconductor or conductor thin film, may be deposited on a substrate using various vapor deposition methods such as sputtering, evaporation and pulsed laser deposition. A significant drawback of these techniques is that the cost of using such techniques becomes quite expensive when they are used on display substrates having large areas.
The deposition of transparent oxide thin films on large area substrates using a liquid solution-phase (i.e., a solution based) process provides a less costly alternative to such vapor deposition methods. However, a significant drawback associated with the use of liquid solutions methods is that often subsequent annealing temperatures greater than 200° C., and even 400° C., are used to produce a thin film with adequate properties and morphology. Such temperatures are unsuitable for plastic substrates since plastic materials may suffer from significant mechanical deformation, melting and/or chemical degradation such as yellowing when exposed temperatures in excess of 200° C.
There is therefore a need for a transparent oxide thin film that can be produced at temperatures lower than 200° C.